Most Popular Topics

**silversaver** · 09-02-2015, 05:12 AM

use the power from gird, much cheaper than what you are looking for. nothing but trouble

**inetdog** · 09-02-2015, 06:32 AM

Originally posted by Jitman530

Hello everyone,

This is my first post and too be 10000% honest, I read alot on solar and there are so many questions that I cannot find the exact answer to so I signed up here hoping you guys here can help me

Some back round information of what I am trying to do. I am setting up a greenhouse that is about 10x10 feet and I will need about 1000 watts on this greenhouse, and it will be off the grid. I live near Sacramento CA and we get ALOT of sun here. Keep in mind, it wont be used year round, probably 8 of the 12 months.

I am planning to use 1000 watts for 6 hours every day. I do not know exactly how to set up my OWN system, I will have a proffessional set it up, however in my area, we only have the small solar companies that try to FORCE you to buy thiere overpriced panels, (1K watt system for 5000$)(WTF?)

Anyways, Some of the questions I have are,

1. During the time the greenhouse starts to use the 1000 watts of light(3 PM to 9PM), where does the 1000 watts come from? does it get pulled from the battery? or does it get pulled from the solar panels?

2. I am planning on buying 4 345 Watt sun power panels for 303$ each, What controller, batteries, and inverted is needed? Any thoughts on those panels?

3. I know solar panels have an efficiency rating, this is a stupid question, but someone tried arguing with me today, and I knew he did not know what he was talking about, He said if a panel is 15% effeminacy and you have 100 watts, than you only get 15 watts an hour? i knew that is not the case, can someone confirm this?
I always assumed a 100 watt panel will give you about 80-90 watts an hour?

4. Is there a supplier where you can get panels cheaper? i know if you buy them wholesale from china you get it 40 cents a watt. And ther a few here in the US around 50-60 cents a watt too. Is there a company someone can reccomend? or a distrubutor, especially here in CAlifronia?

I know I will have more questions, so when it comes up I will ask.

Thanks so much for anyone who helps me

Answers:

You are using 6000kWh per day. Note the "h" which makes it killowatt-hours.
That is quite a lot, into the low end range of whole house solar systems.

1. If you are using an off-grid system (with batteries) some of it will come from the panels as long as there is still useful light on them, the rest will come from the batteries.
What goes to the lights directly will not charge the batteries. 1000kW is a lot of light. First you should be using fluorescent or LED if possible. Are these specialized grow lights?

2. That is a very good price for Sun Power. Are you sure that they are not surplus or rejects? Look for information in the stick threads on how to size your system.
You will not get the full 345W from the panels except on a super ideal day right at solar noon. Maybe 1200W max reasonably. And a total of about 6kW per day. That is not enough to replace 6kW back into the batteries. You need more panels or less load.

3. On a typical point on the earth's surface, at solar noon, a panel will intercept 1000 watts of sunlight for each square meter of panel area, at optimum tilt.
If the panel is exactly one m² and has an efficiency of 20% it will produce 200W of output. That efficiency number is already figured into the nominal power rating of the panel.

4. You can get odd lot panels for as little as $.50 per kW, but will have to pay shipping too.
Legitimate Sun Power panels are, as far as I know, only available through Sun Power installers.

You will end up paying as much as $2.00 per watt for power from a battery system. A grid tied system will not need batteries but will require a permit and signed agreement from the utility.

**azdave** · 09-02-2015, 10:10 AM

You also mention you won't use it four months out of the year. You would be a lot better off financially and the world will be a lot better off environmentally to just use electricity off the grid.

Stay here and read up for a few months and you'll soon see that your idea was not nearly as "green" as you first thought.

**SunEagle** · 09-02-2015, 10:24 AM

Originally posted by Jitman530

Hello everyone,

This is my first post and too be 10000% honest, I read alot on solar and there are so many questions that I cannot find the exact answer to so I signed up here hoping you guys here can help me

Some back round information of what I am trying to do. I am setting up a greenhouse that is about 10x10 feet and I will need about 1000 watts on this greenhouse, and it will be off the grid. I live near Sacramento CA and we get ALOT of sun here. Keep in mind, it wont be used year round, probably 8 of the 12 months.

I am planning to use 1000 watts for 6 hours every day. I do not know exactly how to set up my OWN system, I will have a proffessional set it up, however in my area, we only have the small solar companies that try to FORCE you to buy thiere overpriced panels, (1K watt system for 5000$)(WTF?)

Anyways, Some of the questions I have are,

1. During the time the greenhouse starts to use the 1000 watts of light(3 PM to 9PM), where does the 1000 watts come from? does it get pulled from the battery? or does it get pulled from the solar panels?

2. I am planning on buying 4 345 Watt sun power panels for 303$ each, What controller, batteries, and inverted is needed? Any thoughts on those panels?

3. I know solar panels have an efficiency rating, this is a stupid question, but someone tried arguing with me today, and I knew he did not know what he was talking about, He said if a panel is 15% effeminacy and you have 100 watts, than you only get 15 watts an hour? i knew that is not the case, can someone confirm this?
I always assumed a 100 watt panel will give you about 80-90 watts an hour?

4. Is there a supplier where you can get panels cheaper? i know if you buy them wholesale from china you get it 40 cents a watt. And ther a few here in the US around 50-60 cents a watt too. Is there a company someone can reccomend? or a distrubutor, especially here in CAlifronia?

I know I will have more questions, so when it comes up I will ask.

Thanks so much for anyone who helps me

While I agree that 1kw system you were quoted for $5000 is very high. But a solar/battery system for 6kWh a day will probably cost you 4 times that $5k and then every 4 to 5 years you will spend about $8k to replace the batteries.

If you have grid power within a few hundred feet of that green house it will be less costly to run a power line to it.

If you really want to go with solar then get a "grid tie" system for your home. A larger kw system should be less costly than $5/w up front and then you also can get a 30% Tax refund if you qualify.

**Jitman530** · 09-02-2015, 01:26 PM

Originally posted by inetdog

Answers:

You are using 6000kWh per day. Note the "h" which makes it killowatt-hours.
That is quite a lot, into the low end range of whole house solar systems.

1. If you are using an off-grid system (with batteries) some of it will come from the panels as long as there is still useful light on them, the rest will come from the batteries.
What goes to the lights directly will not charge the batteries. 1000kW is a lot of light. First you should be using fluorescent or LED if possible. Are these specialized grow lights?

2. That is a very good price for Sun Power. Are you sure that they are not surplus or rejects? Look for information in the stick threads on how to size your system.
You will not get the full 345W from the panels except on a super ideal day right at solar noon. Maybe 1200W max reasonably. And a total of about 6kW per day. That is not enough to replace 6kW back into the batteries. You need more panels or less load.

3. On a typical point on the earth's surface, at solar noon, a panel will intercept 1000 watts of sunlight for each square meter of panel area, at optimum tilt.
If the panel is exactly one m² and has an efficiency of 20% it will produce 200W of output. That efficiency number is already figured into the nominal power rating of the panel.

4. You can get odd lot panels for as little as $.50 per kW, but will have to pay shipping too.
Legitimate Sun Power panels are, as far as I know, only available through Sun Power installers.

You will end up paying as much as $2.00 per watt for power from a battery system. A grid tied system will not need batteries but will require a permit and signed agreement from the utility.

Thank you, Your post helps alot. I am actually near a house, near enough to run cords to the back yard, were we will have 2 outlets. and we r using led lights, about 5 220 watters and an ac.

so if I wanted to run grid tie, how many watts of electricty will I need to cover 1000 watts for 6 hours a day? and what do I need for a grid tie?

**Jitman530** · 09-02-2015, 01:27 PM

Originally posted by SunEagle

While I agree that 1kw system you were quoted for $5000 is very high. But a solar/battery system for 6kWh a day will probably cost you 4 times that $5k and then every 4 to 5 years you will spend about $8k to replace the batteries.

If you have grid power within a few hundred feet of that green house it will be less costly to run a power line to it.

If you really want to go with solar then get a "grid tie" system for your home. A larger kw system should be less costly than $5/w up front and then you also can get a 30% Tax refund if you qualify.

I actually can get a grid tie, I think i might get one now

**paul65k** · 09-02-2015, 02:21 PM

Just Sayin'

There are certain "Greenhouse" operations that are better off NOT tied to the grid as there are certain "Greenhouse" operations that like to fly under the radar with regard to anyone (including an electric company) knowing about the usage.......now with that being said........I don't think that in this case a grid tied system just might not be an option........just guessing but this is CA ad we do have some interesting laws about growing certain things in "Greenhouses"

**thejq** · 09-02-2015, 02:41 PM

Originally posted by Jitman530

Thank you, Your post helps alot. I am actually near a house, near enough to run cords to the back yard, were we will have 2 outlets. and we r using led lights, about 5 220 watters and an ac.

so if I wanted to run grid tie, how many watts of electricty will I need to cover 1000 watts for 6 hours a day? and what do I need for a grid tie?

1000 watts = 1 KW, times 6 hr = 6 KWh/day, times 8 month (or 248 days) = 1488 KWh/year. Then you add your house hold usage from your electric bill to get the total usage per year. You can then use http://pvwatts.nrel.gov/ to figure out how big of a solar system you need.

**sirguy77** · 09-03-2015, 11:37 PM

Sunrun- REC 275 Panels

Can someone recommend (PM me) an installer in the San Diego area? I'm looking at Sunrun. However, I would like better panels than REC 275 with power optimizers. They quoted me $21,500 before 30% rebate ($16,300) for a 5.5kW with system 20 panels (S/W facing roof) $3.75 per watt. The price is suppose to be a discount for companies that are part of the SunShares program (negotiated price). My company qualifies for this program. I hear good/bad things about REC panels (10 year product warranty.
25 year linear power output warranty (max. degression in performance of 0.7% p.a.). Just wondering if this is a deal breaker.

Thanks,

Guy...

**J.P.M.** · 09-03-2015, 11:46 PM

Originally posted by sirguy77

Can someone recommend (PM me) an installer in the San Diego area? I'm looking at Sunrun. However, I would like better panels than REC 275 with power optimizers. They quoted me $21,500 before 30% rebate ($16,300) for a 5.5kW with system 20 panels (S/W facing roof) $3.75 per watt. The price is suppose to be a discount for companies that are part of the SunShares program (negotiated price). My company qualifies for this program. I hear good/bad things about REC panels (10 year product warranty.
25 year linear power output warranty (max. degression in performance of 0.7% p.a.). Just wondering if this is a deal breaker.

Thanks,

Guy...

Kind of steep. The going rate is very ~ $3.50/Watt w/ some shopping and sharp negotiatingt. Check w/ local, reputable elec. contractors.

**josefontao** · 09-04-2015, 01:01 PM

Originally posted by sirguy77

Can someone recommend (PM me) an installer in the San Diego area? I'm looking at Sunrun. However, I would like better panels than REC 275 with power optimizers. They quoted me $21,500 before 30% rebate ($16,300) for a 5.5kW with system 20 panels (S/W facing roof) $3.75 per watt. The price is suppose to be a discount for companies that are part of the SunShares program (negotiated price). My company qualifies for this program. I hear good/bad things about REC panels (10 year product warranty.
25 year linear power output warranty (max. degression in performance of 0.7% p.a.). Just wondering if this is a deal breaker.

Thanks,

Guy...

The price is a deal breaker... you can do better. Read the forums. There are lots of people in the San Diego area that have gotten better deals with similar or better equipment using reputable and good installers. You can also search on Yelp and go by reviews.
Once you find an installer, go see jobs that they have recently finished. Gauge the workmanship by how things appear (there is a house near mine that finished solar about 2 months ago and looks like crap).

Contact homeowners and ask how the experience was. Do your homework.

Most Popular Topics

Hello, I am a noob and need ALOT of help

Hello, I am a noob and need ALOT of help

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment